A complex scene includes objects or portions of the scene that are at a wide variety of distances from the camera. In some cases, the scene might have diverse illumination levels, strongly vary in color or polarization throughout the scene, and/or might include objects that move on different time scales.
Digital cameras are the most common imaging system used to image such complex scenes. A typical digital camera contains a single lens (i.e., aperture) that images the scene onto an array of detectors, referred to as a focal-plane array (FPA). Unfortunately, a conventional single-aperture camera only allows one fixed shutter speed, focus position, aperture size, color balance, and polarization per image. As a result, such a camera can not sufficiently capture the diversity of a complex scene, as described above, because typically there is no single combination of aperture stop size, exposure time, focus position, color balancing, and zoom position that can capture the desired level of detail in the scene. This problem is exacerbated when the scene includes a wide area, such as a sporting event, a natural landscape, or even a large room.
Multiple camera systems offer a way to overcome some of the disadvantages inherent to a single-aperture camera. For example, conventional multi-camera systems employ an array of cameras, wherein each images a different portion of a scene. This enables the image to be divided into different zones such that the focus position, aperture size, shutter speed, color balance, and polarization sensitivity could be varied on a zone-by-zone basis as dictated by the range of the objects in the zone, available quantity and hue of illumination, object speed in the zone, and polarization variation due to scattering from oriented surfaces. The images generated by the multiple cameras can then be stitched together to form a composite image of the entire scene. As a result, the composite image can capture at least some of the diversity of a scene.
Although such a multi-camera system overcomes many of the disadvantages inherent to the single-aperture camera, the size of the entrance pupil of each camera in the array must be sufficiently large to resolve features in the scene of interest. Multi-camera imaging systems, therefore, require relatively large lenses and, as a result, tend to be large and bulky. Further, their bulk often gives rise to dead zones in the composite image due to a limit on how close the cameras can be placed to one another.
A compact imaging system having sufficient flexibility to capture highly diverse attributes of a large-area complex scene would be a significant advance in the state of the art.